jcp1967
Well-Known Member
I actually broke a bipod on my lapua with a top ported brake...you got me thinking now...
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How important is seeing the hit
- Thread starter J E Custom
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Varmint Hunter
Well-Known Member
The video is a bit alarming.
However, I have been shooting a 338RUM with a small PK (PainKiller) brake that has 3 holes in the top. The rifle is a semi-custom Rem LSS with the factory laminated stock. Barrel is a fluted #5 contour IIRC.
With nearly 1,000 rounds down the tube, I have experienced no ill effect on the rifle and it still shoots very small groups at 400yds.
JE - thanks for all of the great info that you have provided over the years. I saw this video when you first posted it and it certainly changed my view about brake geometry.
Although a 6.5 Creed doesn't need a brake, I tossed a Vais on mine just to promote smooth shooting from the bench. Interestingly enough, the first brake I ever owned was a Vais.
However, I have been shooting a 338RUM with a small PK (PainKiller) brake that has 3 holes in the top. The rifle is a semi-custom Rem LSS with the factory laminated stock. Barrel is a fluted #5 contour IIRC.
With nearly 1,000 rounds down the tube, I have experienced no ill effect on the rifle and it still shoots very small groups at 400yds.
JE - thanks for all of the great info that you have provided over the years. I saw this video when you first posted it and it certainly changed my view about brake geometry.
Although a 6.5 Creed doesn't need a brake, I tossed a Vais on mine just to promote smooth shooting from the bench. Interestingly enough, the first brake I ever owned was a Vais.
J E Custom
Well-Known Member
Rich, The tuning process is impossible for mass produced brakes because they are all machined the same and not for specific rifles/cartridge combinations.
When I first started testing and designing muzzle brakes, I merely
wanted to see if I could improve the recoil reduction over the best brakes available for on my rifles. the design took many turns and lots
of things were learned by testing. each time we tested a new design we used the same rifle and load. We also tested the rifle without a brake first to benchmark the recoil in case anything had changed.
The best brake we found at the time would produce 51 to 58% depending on the rifle/load combination. Puzzled buy this difference in performance I went back to the drawing board and tried to Understand why there was a difference in recoil using different cartridges.
Each cartridge has a powder to gas ratio and there is the difference in performance. What I found was a way to adjust the brake to take advantage of this difference. once I understood the problem I had to develop a tuning formula for every combination of powder, bullet found in different cartridges.
The results are surprisingly good and the percentage of recoil reduction is on average 10% better with the brake tuned for the cartridge/load combination than one that is not tuned.
The fact that brakes that are mass produced are not tuned limits there performance. I am not in the business of making brakes so I don't have any ax to grind with any brake manufacture because even the poorest design reduces recoil which helps the shooter that is recoil sensitive.
I only wanted to find out what makes a muzzle brake work and prove things that are wrong with many that reduce there performance.
A Lot of muzzle brake designs target looks and tricks that appeal to some because of the WOW factor but in realty, don't do a very good job of reducing recoil. (The reason for installing a muzzle brake in the first place)
J E CUSTOM
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Rich Coyle
Well-Known Member
J E Custom,
I don't remember why I started making brakes. I certainly am entertained by testing. My gunsmith asked me to make one with angled ports and threaded on both ends. So I did. Results on the slide:
With no brake the total travel in the free recoil was 39 5/16".
With the slots facing forward the total for the three shots was 11 1/2".
With the slots facing rearward the rifle moved a total of 4 9/16".
So even with the slots facing the "wrong" direction it is still better than no brake.
I don't remember why I started making brakes. I certainly am entertained by testing. My gunsmith asked me to make one with angled ports and threaded on both ends. So I did. Results on the slide:
With no brake the total travel in the free recoil was 39 5/16".
With the slots facing forward the total for the three shots was 11 1/2".
With the slots facing rearward the rifle moved a total of 4 9/16".
So even with the slots facing the "wrong" direction it is still better than no brake.
I'm glad some one revived this old thread.
Nice video JC...I just built a 6.5 Grendel on an AR platform. Most all AR barrels are threaded, so I needed something to screw on the end.
I chose a artillery style brake, but it has three holes on top. It is stainless and only cost $16.00 on ebay.
Looks like I might needed to tap the holes in the top. My accuracy wasn't great even though this a dirt cheap barrel so I wasn't expecting a lot. But it is good to know so I don't damage a rifle.
I have another one coming for another Grendel rebuild I just finished over the weekend.
So I have 6 holes to fill.
That said...I wonder how much force I'm getting on a chambering that is this small?
27 to 30 grains of powder is pretty lite load compared to 60 to 70 grains in the big magnum rifles.
Nice video JC...I just built a 6.5 Grendel on an AR platform. Most all AR barrels are threaded, so I needed something to screw on the end.
I chose a artillery style brake, but it has three holes on top. It is stainless and only cost $16.00 on ebay.
Looks like I might needed to tap the holes in the top. My accuracy wasn't great even though this a dirt cheap barrel so I wasn't expecting a lot. But it is good to know so I don't damage a rifle.
I have another one coming for another Grendel rebuild I just finished over the weekend.
So I have 6 holes to fill.
That said...I wonder how much force I'm getting on a chambering that is this small?
27 to 30 grains of powder is pretty lite load compared to 60 to 70 grains in the big magnum rifles.
J E Custom
Well-Known Member
If you thread all three in the one brake, you can play with pluging one at a time, and if you end up with one open with good results you may want to only plug two on the other one.
The other option is to plug all 3 on each one and be done.Recoil reduction may be slightly less because these holed do add to the total gas that is discharged, but the side effects are far worse.
If you have an I Phone, you can set it on slow motion to video, and place the rifle in a rest that allows the muzzle to move or the butstock (With restraints that prevent it from jumping out/off) and then play back the Video and you may be able to see this same effect while adding plugs to help you decide what is best, one or none to leave open.
The reaction is the same but with small powder charges the effect is less. the main problem we found with top ports was the unaposed ports. Brakes with aposing ports with the same volume of gas discharge were more consistant and allowed the rifle to react as designed. there may be some muzzle rise but with a good muzzle brake design it is almost eliminated and still allows you to see the hit.
J E CUSTOM
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J E Custom
Well-Known Member
You are absoultly correct. The poorest muzzle brake design reduces recoil to some extent because it diverts the gas away from the bore center line. How well it does this is in the design and volume of gas that it can handle.
We also found that you can have to much port opening, and lose some effiecency. So for the guys with smaller cartridges, a smaller brake sometimes works better. We use the cartridge case capacity to calculate the volume of gas the brake must handle and decide what the port volume and number of ports required to get the best performance.
Some brakes are simply a piece of metal with some ports or holes drilled in it, Other brakes (The better designs) has much more thought in the function and as a result, they produce better recoil reduction.
Even though brakes look simple, there is a lot of sience involved to get the most performance.
J E CUSTOM
jcp1967
Well-Known Member
I have 2 top ported brakes and this is a scary video. My 338 lapua is a sporter with a benchmark #5 on it...Accuracy is excellent but Im thinking the bullet would already be clear before the flex could happen with the barrel...thinking of changing to a radial. my wife has a 26 nos with a 3.5 contour and the same brake...She obviously gets less downforce than I do but Im still concerned.
J E Custom
Well-Known Member
Yes, the bullet has cleared the brake before the reaction of the top ports that Push the barrel down with little or no effect on accuracy, at least in the beginning. the problem you see on the Video is the long term effects on bedding and possibly A stock failure.
Down force is only good in the eyes of the shooter. It is bad for the rifle unless it is minimal and then it just prolongs the problems.
If you only shoot off hand it lessens the damage because a person cannot totally stop this reaction to the unopposed ports.
J E CUSTOM
